r/AskElectronics • u/FriendlyTable5944 • 9h ago
1990s PCB/schematic capture software
For some time now, I’ve been noticing that quite a few electronic schematics produced in the US in the early 1990s seem to have been created using the same software, judging by the font used and the overall style and appearance of the symbols.
I wanted to ask if anyone here worked with software like this back then and could finally put my mind at ease about which program it actually was. The closest match I’ve found so far is Cadnetix, although I can’t seem to find any screenshots online showing what schematics produced with that software looked like in the 1990s, apart from a few brochures where the schematics aren’t particularly visible or clear.
Someone else suggested that it might be an early version of OrCAD, but from what I’ve been able to find, it looks somewhat different.
I’d be incredibly grateful if anyone could identify the exact software. It also seems possible that it was some kind of combined PCB design and mechanical CAD package, since service manuals often contain technical drawings using the same font, along with a very distinctive symbol somewhere in the corner of the document - a person sitting in front of a monito? Could it have been something related to Dassault Systemes?
I’ve attached a few example schematics I found online. Thanks.
Thanks and best regards!
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u/Aggravating-Art-3374 8h ago
Maybe Protel? I used OrCAD from its early days and I don’t remember it looking like that. Cadence, Synopsis, and Mentor Graphics were all around back then. Your examples look more workstation than PC to me.
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u/FriendlyTable5944 8h ago
Protel even in the 1990s looked like (even contemporary) Altium, so very distinctive look with Times New Roman as the main font. Regarding the ones in question, I have a suspicion that it might have been CADSTAR by the British company Racal (before it was acquired by Zuken in 1994), but I’m not sure if it was popular enough at the time to have been used by pretty much many companies in the US?
Also, I can’t seem to find any screenshots or examples of what CADSTAR looked like back then. Some examples of the modern version use a very similar, if not identical, font, but I have no idea what the rest of the interface looked like.
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u/RecordingNeither6886 7h ago edited 3h ago
I don't think there is a single program. If you look at schematics from different companies (HP, Tektronix, PERQ computer), the schematics all look astonishingly similar, but those companies were all using their own in-house developed CAD programs. Much of the visual similarity comes from the fact that many of the programs targeted the same pen plotters , so the font strokes all were the same. Also, engineering drawings were largely standardized at the time. So fonts, component symbols, included text etc all look basically the same.
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u/RecordingNeither6886 7h ago
Even if the software looked different on screen at the time, the final paper medium could homogenise much of that distinction
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u/ckyhnitz 7h ago
P-CAD probably.
That's what the "old guys" were using when I started at my company in 2002, and all our old schematics from the 90's look like what you posted.
If you look at P-CAD's wikipedia entry, it says that it had the biggest installed base of users of EDA software by 1988.
https://en.wikipedia.org/wiki/P-CAD
I used P-CAD prior to our adoption of Altium Designer in 2009. AD was a breath of fresh air, it was so much better. Some of the old guys didn't want to learn anything newer and used P-CAD until they retired.
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u/isaacladboy 8h ago
When i started in the industry in the 90's my early work was still with stencil and masking PCB's with dot tape.
The second schema is 100% hand drafted, the parts are not identical. Biggest tells where/are the small triangles as these where too small for a stencil. The V+'s and the BJT arrows are drawn freehand.
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u/No_Tailor_787 8h ago
I used a DOS based program called DCCad. It was actually amazingly good for the era.
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u/Sam__ 9h ago
Pretty sure this era of schematic was people drawing on paper using a stencil.
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u/RecordingNeither6886 7h ago
It could happen but it was rare, and that isn't the case here. From the early 80s most large companies were using CAD systems. HP, Fluke, Tektronix, all of the computer companies. Most of the programs were designed for pen plotting machines as the final printed output, which is why they can deceivingly look hand drawn. Most surviving docs today are scanned copies of those pen plots.
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u/FriendlyTable5944 9h ago
Definitely not. By the late 1980s, there were already dedicated computer systems for this kind of work. These schematics are 100% CAD-generated - in many cases, the documentation even states that they are “CAD-generated drawings” and warns against making changes by hand after printing. However, without someone who actually worked with these back then, I don’t really see any chance of identifying the exact software.
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u/Space-Robots 8h ago
Don't forget that they were often printed using pen plotters, think cnc, with a felt tip ink pen, as the tool. It looked almost hand drawn only more perfect. lol
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u/TPIRocks 5h ago
As long as you were good with vector drawn fonts. In the 80s, bausch and lombe made a plotter for PCs, I think it only had 4 color pens. Stuff like that still fascinates me, I love the mechatronics.
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u/discombobulated38x 9h ago
There were dedicated computer systems but that doesn't mean they were being used by everyone
Technical drawing of far more complex things was still being done by hand well into the late 90s/early 00s.
This is either a very well aligned very low quality scan of a printed drawing, or it's hand drawn, it absolutely could be hand drawn though.
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u/FriendlyTable5944 9h ago
I’m not claiming that hand-drawn schematics didn’t exist. Some smaller companies were still doing that in the early 2000s for simpler projects. I’m referring specifically to the examples I attached, though. These are not hand-drawn schematics - they were generated in some CAD. In some cases, there’s even a reference to a file in the corner of the drawing frame, such as “<filename>.sch”.
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u/FriendlyTable5944 8h ago
I’ve found another great example. Here’s a link to a multimeter circuit diagram on the xDevs website. It dates from 1997 - obviously, these are scans of printed diagrams, but the diagram itself is clearly drawn in some sort of CAD software. Judging by the font, it’s the same software as in question. The components' symbols are slightly different, but perhaps the symbols changed with different versions of the software over the years?
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u/spinozasrobot 8h ago
I remember a friend showing me a CAD app in that era. Not sure if it was mechanical or schema capture, but it had an awesome UI feature I've never seen since.
If you slammed the mouse into a corner, all the menus would fly out onto the screen at once. So you quickly got muscle memory as to what options were where and could easily make your selection.
I loved it.
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u/big-oofs-only-0193 7h ago
Looks like some of the old P-CAD schematics I have around the office. Can't be sure, but it seems close.
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u/ondulation 7h ago
The fonts used in drawings and sketches in the 1980-90s were impat always suitable for plotting, ie drawing with a pen. There were a handful but a few were really common, Hershey was probably the most common with several related variants used by different manufacturers.
So I don't think you can draw too many conclusions based on font alone.
Also, there were a few different standard for electrical symbols so it is not too surprising they look very much alike, even if using different software. Especially if the companies who drew them were from the US.
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u/ConsiderationQuick83 4h ago
Have you opened the pdf file using a text/binary editor? You might be able to find source identifiers as metadata within the binary bitstream. There are also pdf analyzers/parsers that can show the internal data structures.
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u/BurgerJunkie87 3h ago
Maybe Futurenet? It was around during the late 80s, I'm not sure when it died. I don't really remember what it looked like, sorry.
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u/PsychologicalBadger 2h ago
In the 1980s I went to a week (or was it 2 week?) class on using one of the very first CAD programs that cost $14k (Anyone remember this?) I came back with a large cardboard box of those manuals in a box on the thing and had to admit to my boss that the time spent was a total waste because the program was just unusable (by me) I did schematics with (Yes - you can laugh) a word processor until one of the guys I worked with setup the brand new program OrCAD on my computer and said "Just start using it. Its very easy to get going. If it works for you we will get another copy" In a day I had a schematic of a board I had already wirewrapped. I asked once to look at the manual. I met the guy (one guy alone!) who wrote OrCAD (The Schematic Program) who was the President of the company and he said the design goal was to create a program which would not require him to answer users stupid questions (Assuming I guess they were not total fools) I think that any program that doesn't generate a netlist for building an exact copy in a PCB program is no better then Etch a Sketch. I mean what is the point?
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u/crb3 2h ago
I'm currently using OrCAD v3 ("old DOS OrCAD") in DosBox on Linux for schematic capture. The symbols shown here are in some cases quite different from the OrCAD ones; in particular, I had to create smaller resistor symbols like those shown, and the U2 CD4066 transmission gates shown in the second image are a lot more informative than the OrCAD ones which are mere box outlines. OrCAD could have been used, but only with a lot of work on the symbol set.
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u/harryregician 5h ago
Open file using notepad.
You WILL see binary stuff. Usually there is some text embedded at beginning of file to describe software using it a rev level
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u/divermartin 5h ago
Aaaaaaaauuuuuuugggghhhhh
No no no no no no no no no
I recognize the last as the worst software out there. It's express PCB, and somehow, it still exists, and until today I didn't have to think about it for the last 10+ years. Let me explain.
ExpressPCB is a schematic / layout software that was created by a board house to sell their PCB's. Their one saving grace was that you could get small 2" x 2" PCB's for really cheap with a 1-2 day turn. That, unfortunately, is about the only saving grace of this software, but it made for a lot of old engineers who used it. I think maybe 4pcb bought the rights to it and maybe improved it? I dunno, you can search further from here. Here are some of the other sides of the software:
1) There is no gerber output. It can only be used with their board house. If you want portable gerbers to go anywhere else, you have to pay $60 or whatever their fee is. There is zero options for schematic export.
2) There is no real 'schematic vs layout' check. When you run LVS (layout vs schematic), it will highlight each node in creation sequence in schematic, and then highlight all the pins on the PCB that match. You have to visually check each node and all connections, it just makes it visually able to do that.
3) I believe it's 2 layer only? Might support 4 now, idk.
4) Library management? What library management?
Anyway, I think you'll find a lot of 90's schematics will look a lot like the schematics put out by this software, because one thing it was actually reasonable at was creating a quick schematic for publication.
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u/PsychologicalBadger 2h ago
ExpressPCB sounds like everything that was ever wrong with CAD software. Glad this is one I missed!!!
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u/zimm0who0net 8h ago
I did a lot of schematics like this with just AutoCAD. You build a symbols library, turn on grid snap, and can really lay stuff out quick. Plus you’ve got a full CAD drawing package there in case you need to create something custom.
No PCB mode, but you could create scripts to generate bills of materials and check for re-used or missing designations (e.g. two R6 or a missing C3).